Apple's iPhone and iPad helped make mobile devices a key driver of Thanksgiving and Black Friday e-commerce this year, according to a report from IBM Coremetrics.

Online Thanksgiving shopping grew by 39.3 percent year over year, creating momentum that continued into Black Friday, where online sales grew by 24.3 percent compared with the same period last year, said the report (PDF).

And Black Friday witnessed the arrival of the mobile deal seeker, who embraced his or her mobile device as a research tool for in-store and online bargains. Mobile traffic came close to tripling year over year, to 14.3 percent on Black Friday 2011 from 5.6 percent last year.

The iPhone and the iPad accounted for 10.2 percent of all Black Friday online traffic. The iPhone and the iPad ranked first and second for mobile device retail traffic (5.4 percent and 4.8 percent, respectively). Android-based devices came in third at 4.1 percent.

But it's not all about mobile browsing. The value of individual orders also increased, while the number of items purchased decreased. Home goods, for example, saw an average order-value increase of nearly 16 percent, while the number of items per order dropped by more than 6 percent.

Here's a rundown of the report's other key findings:

Sales on mobile devices surged year over year, to 9.8 percent from 3.2 percent.

Shoppers using the iPad accounted for more actual purchases per visit than shoppers using other mobile devices, with conversion rates reaching 4.6 percent for the Apple device versus 2.8 percent for overall mobile devices.

Mobile shoppers demonstrated a laser focus that surpassed that of other online shoppers, with a 41.3 percent bounce rate on mobile devices versus a rate of 33.1 percent for shoppers on other computing gadgets. The bounce rate records how often people jump from one site to another looking for the best deal on a particular item, rather than browsing around through various items in a more leisurely fashion.

Shoppers referred from social networks generated 0.53 percent of all online sales on Black Friday. Facebook led the pack, accounting for 75 percent of all traffic from social networks.

And while stores like Macys offered "doorbuster" sales to bring more customers into its brick-and-mortar locations (and ostensibly spend more money in them), a greater number of people appear to be splitting their purchasing between online and retail.

The National Retail Federation estimates that as many as 152 million Americans are expected to shop this weekend, up from last year's 138 million.

Update, 5:10 p.m. PT:

In a blog post today, Stephen Baker, vice president of the NPD Group's Industry Analysis unit, reported preliminary results from NPD's Anatomy of Black Friday study. Among the findings:

Almost 65 percent of tech shoppers actually ponied up for a product because they found it on sale, and 28 percent took advantage of big sales at a specific retailer they had targeted. Totals in both those categories were about 50 percent higher than the corresponding totals for shoppers overall, and both the tech totals reflected a 10 percent increase year over year.

Electronics continued to be the second most popular category, after clothing, with more than 23 percent of Black Friday shoppers buying some type of electronic gadget--15 percent more than last year and 50 percent higher than the third most popular category, toys.

TVs saw their popularity leap 30 percent from last year, overtaking computers as the most popular electronics product (excluding purchases of video games from the computers category).

Big-screen TVs seemed to be preferred to their smaller-screen brethren, with 26 percent of Black Friday tech shoppers saying they plan to spend more than $1,000 during the holidays. That's 10 percent more than last year and compares with 19 percent of overall shoppers who said they planned to spend that much.

Electronics retailers did nicely, with Best Buy coming in as the fourth most visited retailer behind Wal-Mart, Target, and Amazon--all sellers that offer a much wider range of products. And Best Buy saw its total number of shoppers fall less sharply than did other retailers, as numbers dipped across the board. Plus, 58 percent of Best Buy shoppers actually shelled out for merchandise, versus 38 percent last year, the biggest such bump among the top four retail outlets.